Reliable design of THz absorbers based on graphene patterns: Exploiting genetic algorithm

Najafi, Alireza; Soltani, Mohamadreza; Chaharmahali, Iman; Biabanifard, Sadegh

doi:10.1016/j.ijleo.2019.163924

Cited by 45 publications

(13 citation statements)

References 29 publications

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“…The use of graphene in THz devices has been greatly interesting. In line with this, varieties of graphene-based THz absorbers have been reported in the literature [48][49][50]. In this communication, we investigate certain grapheneembedded periodic structures in respect of the transmission properties.…”

Section: Revised Manuscriptmentioning

confidence: 63%

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF₂ Defect Layer

Pourmand

Choudhury

2020

IEEE Access

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Investigation of the spectral response of graphene-dielectric (SiO 2 )-based periodic structure was made in the far-infrared (IR) to the mid-IR frequency range, and the effects of different parametric and operational conditions on the transmission characteristics were explored. The presence of stop-bands, followed by Bragg reflection harmonics, in the low-frequency regime was observed exploiting the bilayer graphene (BLG) sheets. The width of stop-bands could be tuned by altering the number of periods as well as the chemical potential of BLG. The formation of a stop-band (with a transmission dip positioned at ~16 THz) having a span of ~3 THz was noticed, which is possibly a very large stop-bandwidth reported so far. The structure was also analyzed upon introducing a defect layer of MgF 2 having a thickness smaller than the dielectric medium. This results in shifting the position of stop-bands of the structure. The characteristics of transmission spectra were found to be greatly depending on the chemical potential (of BLG) and other operating conditionsthe feature that triggers the usefulness of the proposed structure in the design of optical modulators, tunable narrow-band filters and broad-band reflectors.

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Section: Revised Manuscriptmentioning

confidence: 63%

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF₂ Defect Layer

Pourmand

Choudhury

2020

IEEE Access

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“…Finally, a continuous graphene sheet is placed on top of the whole device to enhance total absorption. Compared to conventional designs in References 1‐12, two first layers benefit from an extra bias, which leads to more degree of freedom to adjust input impedance using external control parameters (gate biasing).…”

Section: Proposed Configurationmentioning

confidence: 99%

“…The matching may become complex since device input impedance is heavy, huge and nonlinear. Even some works 7 established an evolutionary algorithm‐based approach to optimize design parameters.…”

Section: Introductionmentioning

confidence: 99%

Highly tunable multi‐band THz absorber with circuit model representation using multi‐bias scheme

Aghaee

Orouji

2020

Int J Numerical Modelling

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Utilizing a double bias scheme for graphene patterns as a single layer, a THz meta-surface structure is proposed. The structure includes two dual bias layers and a graphene continuous sheet on top. So five possible biases are available which lead to a highly tunable absorption response. All consisting parts are modeled via passive circuit elements to obtain whole device input impedance. Then impedance matching theory is used to investigate potential frequencies for perfect absorption. Also, ample simulations are performed to show the validity and accuracy of theoretical descriptions. According to the simulation results in the conventional finite element method as a reference approach is in acceptable agreement with the developed circuit model approach. The proposed structure shows nearly perfect absorption in 5, 6, 7, and 8 THz with absorption rate over 90%. Such a tunable reaction is in incredible requests in optical systems and has various applications in structuring sensors, modulators, and photonic functions.

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“…The main idea behind this perfect absorber is to simultaneously provide impedance matching criteria and using loss substrates. Until now, numerous works have investigated MAs in wide variety of applications such as security imaging, biomedical detection, indoor communications, and energy harvesting 2–8 . Most of state of art studies have been concentrated on the desired frequency range to achieve broadband, 9 perfect tunable, 10 multi‐band, 11 and dual‐band 12 absorbing responses.…”

Section: Introductionmentioning

confidence: 99%

“…Until now, numerous works have investigated MAs in wide variety of applications such as security imaging, biomedical detection, indoor communications, and energy harvesting. [2][3][4][5][6][7][8] Most of state of art studies have been concentrated on the desired frequency range to achieve broadband, 9 perfect tunable, 10 multi-band, 11 and dual-band 12 absorbing responses. Instead, some systemic design procedures are introduced to design MAs at THz spectrum.…”

Section: Introductionmentioning

confidence: 99%

Manipulating pattern periods via external bias for graphene‐based THz Dual‐Band absorber

Aghaee

Orouji

2021

Micro & Optical Tech Letters

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Electrical control of terahertz (THz) radiation for high‐performance THz imaging is the key point. The spectrum suffers from a lack of active and available materials such as graphene have a severely limited bias range leading to restricted tuning. Therefore, here we demonstrated an efficient tunable device exploiting a triple bias layer for patterned graphene ribbons. Here, the patterned graphene acts as a tunable surface impedance leads to electrically controlled impedance matching between the device and free space. So, a dual‐band absorption is obtained which is appropriately robust against incident angle and capable of adjusting absorption peaks. The major contribution of the design is capability of manipulating patterns periods via gate biasing. This causes providing additional degree of freedom compared to conventional graphene patterns. According to the simulation results, the proposed device shows excellent tuning operation via gate bias voltages.

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Reliable design of THz absorbers based on graphene patterns: Exploiting genetic algorithm

Cited by 45 publications

References 29 publications

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF₂ Defect Layer

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF₂ Defect Layer

Highly tunable multi‐band THz absorber with circuit model representation using multi‐bias scheme

Manipulating pattern periods via external bias for graphene‐based THz Dual‐Band absorber

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Reliable design of THz absorbers based on graphene patterns: Exploiting genetic algorithm

Cited by 45 publications

References 29 publications

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF2 Defect Layer

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF2 Defect Layer

Highly tunable multi‐band THz absorber with circuit model representation using multi‐bias scheme

Manipulating pattern periods via external bias for graphene‐based THz Dual‐Band absorber

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Product

Resources

About

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF₂ Defect Layer

Wideband THz Filtering by Graphene-Over-Dielectric Periodic Structures With and Without MgF₂ Defect Layer